If you like to control depth of field but don't want to manually figure out exposures, shoot AV. Manual if you want full control, but you have to understand how your light meter is working, and also how the three pillars of exposure interact.

anyhow when taking portrait specially outside the background should be blurred (DoF?)

oki ill make it easy for myself about the aperture let say the lowest number (1. the wider the "IRIS" is and the background will be blurry, the highest number (22) the "IRIS" will become small and the background/whole scene will be in focus.

so to make the whole scene in focus I need a high number (f/higher than 1.8 or so).

when cropping will you just use the crop tool and just crop the desired size or image that need to be cropped?

If you like to control depth of field but don't want to manually figure out exposures, shoot AV. Manual if you want full control, but you have to understand how your light meter is working, and also how the three pillars of exposure interact.

Also, what article said not to focus on the eyes?!

I'd be interested to read which article says not to focus on the eyes when shooting portraits too!

I usually focus on the nearest eye of the subject but don't open the lens up to it's maximum aperture. Most lenses give their best image quality stopped down a little so with my 85mm 1.8f I would use f2 or f2.8 depending on the lighting and background. This will still give nice bokeh if your subject is a reasonable distance from the background, say 5ft minimum.

not an expert portrait photographer by any stretch of the imagination and since focusing on eyes is the way to go, if possible or if you have to choose one eye try and focus on the right eye. The left if you are looking at them, for some reason first eye people look at is right eye. Seems silly but true, try yourself when looking at other people, it seems to work better.